Microsoft Corp (MSFT) Chief Executive Satya Nadella may unveil an iPad version of the company's Office software suite on March 27, a source told Reuters, potentially using his first major press outing to launch the company's most profitable product for Apple Inc's popular tablet.

Nadella, who replaced longtime CEO Steve Ballmer earlier this year, will address the media and industry executives in San Francisco on March 27.

Investors for years have urged Microsoft to adapt Office for mobile devices from Apple and Google Inc, rather than shackling it to Windows as PC sales decline. But the Redmond software giant has been reluctant to undermine its other lucrative franchise, its PC operating software.

Microsoft gives up some $2.5 billion a year in revenue by keeping Office off the iPad, which has now sold almost 200 million units, analysts estimate.

Tech blog Re/code first reported news of Nadella's event. Microsoft declined to comment on the specifics of the CEO's appearance.

(Reporting by Bill Rigby; Editing by Steve Orlofsky)